Haz Mat Ch.2 Flashcards
What does Hazard Class 2 comprise?
Gases
Hazard Class 2 includes materials in a gaseous state at normal temperatures and pressures.
How are gases in Hazard Class 2 typically stored?
In pressure containers or cryogenic liquid storage tanks
This is necessary for safe transport and storage of gases.
What are the three divisions of Hazard Class 2?
- Division 2.1 Flammable gases
- Division 2.2 Nonflammable, non-toxic gas
- Division 2.3 Toxic gases
Each division is based on the type of potential hazard posed by the gases.
What types of potential hazards are associated with gases in Hazard Class 2?
- Energy (flammable or oxidizer)
- Toxicity (including asphyxiation)
These hazards dictate the safety measures needed during handling and transport.
True or False: Division 2.2 gases are flammable.
False
Division 2.2 includes nonflammable, non-toxic gases.
Fill in the blank: Division 2.3 of Hazard Class 2 includes _______.
[Toxic gases]
Toxic gases can pose significant health risks.
What is Hazard Class 3?
Hazard Class 3 is comprised of flammable liquids, including combustible liquids in the U.S.
What are the primary characteristics of flammable and combustible liquids?
They ignite and burn with relative ease and exhibit varying degrees of toxicity.
What incidents commonly involve Hazard Class 3?
Many hazmat incidents, such as gasoline and diesel fuel spills, involve this hazard class.
What additional hazard can some flammable liquids exhibit?
Some flammable liquids are also corrosive.
Are there divisions for Class 3?
There are no divisions for Class 3.
What can flammable and combustible liquids give off during transport?
They may give off hazardous vapors that can travel from their source.
What happens to vapors from flammable liquids if ignited?
These vapors will burn if ignited.
What are the primary hazards of flammable and combustible liquids?
The primary hazards are chemical energy, corrosivity, and toxicity.
What are some examples of thermal hazards associated with Hazard Class 3?
Fires and vapor explosions.
What is a potential asphyxiation hazard of flammable liquids?
Heavier-than-air vapors can displace oxygen in low-lying and/or confined spaces.
What chemical hazards can be produced by fires involving flammable liquids?
Toxic and/or corrosive gases and vapors.
What mechanical hazard can occur with containers exposed to heat or flame?
A BLEVE, caused by a vapor explosion.
How can vapors from flammable liquids behave?
Vapors can mix with air and maintain cohesion long enough to encounter an ignition source at some distance from the origin.
What environmental hazard can result from flammable liquids?
Pollution caused by runoff from fire control.
What are Class 4 materials?
Class 4 materials include three main categories: flammable solids, spontaneously combustible liquids and solids, and dangerous when wet substances.
What are flammable solids?
Flammable solids are materials in the solid state that can readily combust in the presence of an ignition source without changes to density or pressure.
What are spontaneously combustible materials?
Spontaneously combustible materials may be liquids or solids that can ignite within five minutes after coming in contact with air without an external ignition source.
What are dangerous when wet substances?
Dangerous when wet substances become spontaneously flammable or give off flammable or toxic gas when in contact with water.
What challenges do responders face when extinguishing Class 4 fires?
It may be difficult for responders to extinguish fires involving Class 4 materials due to violent reactions during extinguishment.
What are the three divisions of Class 4 materials?
The three divisions in Class 4 are:
1. Division 4.1 Flammable Solids
2. Division 4.2 Spontaneously Combustible Materials
3. Division 4.3 Dangerous When Wet
What are the primary hazards of Class 4 materials?
The primary hazards of Class 4 materials are chemical energy, mechanical energy, corrosivity, and toxicity.
What are some examples of hazards associated with Class 4 materials?
Examples include thermal hazards, spontaneous fires, vapor explosions, molten substances, chemical hazards, severe chemical burns, and mechanical effects from BLEVE.
What can happen when Division 4.3 materials come into contact with water?
Division 4.3 materials can produce corrosive solutions or flammable gases, such as hydrogen gas or calcium carbide, upon contact with water.
What environmental hazards can result from Class 4 materials?
Environmental hazards include pollution caused by runoff from fire control.
What materials are included in Class 5?
Class 5 materials include oxidizers and organic peroxides.
What are oxidizing materials?
Oxidizing materials are liquids or solids that readily give off oxygen or other oxidizing substances.
What do oxidizers do chemically?
Oxidizers react chemically to oxidize combustible materials.
What is the effect of oxidizers on combustion?
Oxidizers vigorously support combustion, may be explosive, and when combined with fuel, may burn continuously.
What are organic peroxides?
Organic peroxides are oxidizers with a specific chemical composition that make them prone to reactivity.
What can initiate a fire or explosion with organic peroxides?
A small amount of heat, friction, or pressure can start a fire or explosion.
What dual role do organic peroxides play?
Organic peroxides are both a fuel and an oxidizer.
How should organic peroxides be stored?
Organic peroxides should be stored below the maximum safe storage temperature (MSST).
What happens if organic peroxides reach the self-accelerating decomposition temperature (SADT)?
They undergo a chemical change and may violently release from their packaging.
What affects the time before reaction of organic peroxides?
The time before reaction depends upon how much the SADT is exceeded, which can greatly accelerate the decomposition.
Temperature below which the product can be stored safely. This is usually 20-30 degrees cooler than the SADT temperature, but may be much cooler depending on the material
Maximum Safe Storage Temperature
(MSST)
Lowest temperature at which product in a typical package will undergo a self-accelerating decomposition. The reaction can be violent, usually rupturing the package, dispersing original material, liquid and/or gaseous decomposition products considerable distances
Self-Accelerating Decomposition Temperature (SADT)
What are organic peroxides and other materials that have SAD Ts?
Organic peroxides are not the only materials to have SAD Ts; many polymerization initiators or reactive chemicals also have an SADT.
The responder should recognize these materials by using an SDS or other reference source to obtain this data.
How is SADT often indicated in an SDS?
Many times, the SADT is written into the SDS as decomposition temperature.
What is the definition of an oxidizing substance?
An oxidizing substance initiates or promotes combustion in other materials, either causing fire itself or through the release of oxygen or other gases.
What are the two divisions of Class 5 materials?
Class 5 has two divisions: Division 5.1 Oxidizers and Division 5.2 Organic Peroxides.
What are the primary hazards of Class 5 materials?
The primary hazards include thermal hazards, explosive reactions, mechanical hazards, chemical hazards, and asphyxiation hazards.
What are thermal hazards associated with Class 5 materials?
Thermal hazards include heat from fires that may explode or burn hot and fast, or materials/substances sensitivity to heat, friction, shock, and contamination.
What are explosive reactions related to Class 5 materials?
Explosive reactions can occur from contact with hydrocarbons (fuels).
What mechanical hazards are associated with Class 5 materials?
Mechanical hazards include violent reactions and explosions, and sensitivity to heat, friction, shock, and/or contamination with other materials.
What chemical hazards are associated with Class 5 materials?
Chemical hazards can arise from toxic gases, vapors, dust, and from products of combustion, resulting in burns.
What thermal hazards arise from Class 5 materials?
Thermal hazards can result from ignition of combustibles, including paper, cloth, wood, etc.
What asphyxiation hazards are associated with Class 5 materials?
Asphyxiation hazards can occur from the accumulation of toxic fumes and dusts in confined spaces.
What are Hazard Class 6 products?
Hazard Class 6 products are toxic and infectious substances.
What types of materials are included in Hazard Class 6?
Class 6 materials include poisons, poison inhalation hazards, and infectious substances.
What is the health hazard of Class 6 substances during transportation?
Class 6 substances are so toxic to humans that they pose a hazard to health during transportation.
What are the two divisions of Hazard Class 6?
The two divisions are Division 6.1 Toxic substances and Division 6.2 Infectious substances.
What does the ‘*’ indicate in Division 6.1?
The ‘*’ indicates that the words poison or poisonous may be used interchangeably with the word toxic during domestic transportation.